When people think of drones and natural disasters, they imagine search-and-rescue (SAR) drones directing rescue teams to victims in need of immediate assistance. However, the actual use of drones in natural disasters is quite different. Forget SAR: “In the last year and a half (in the U.S), the American Red Cross used drones to conduct overall assessment of damage as well as detailed damage assessment of residential homes,” said Brad Kieserman, the American Red Cross vice president of disaster operations and logistics. “We also make considerable use of drone video footage that we get from our partners—both in and out of government— to do broader scope damage assessment: what neighbors are inaccessible, what the overall level of damage is, how high the water is and where it’s impacting.”

“On an international level, the Red Cross is using drones to collect imagery and data for our disaster preparedness and recovery work,” Kieserman said. “In the Philippines, where we are still helping people recover from Typhoon Haiyan, we’re using drones to gather aerial imagery. The imagery is a valuable resource for response, planning, monitoring, and resilience-building activities in these disaster-prone areas.”

Why Drones?

Helicopters are better suited for SAR: They have the personnel and the lifting power to get victims out of harm’s way as soon as they are spotted. Drones do not.

Still, there are many reasons to use unmanned drones for damage assessments rather than SAR missions. Airborne humans are not required to conduct aerial damage assessments. Drones equipped with high-resolution cameras and wireless data downlinks will do just fine.

Furthermore, drones are faster and cheaper to deploy and fly than manned helicopters and fixed-wing aircraft. Speed and cost-effectiveness matters during and after a disaster, when rescue officials need to get the most mileage from their emergency response budgets.

“One of the good things about drones is that generally they are more readily available in quantity in a disaster scene, than say helicopters or fixed-wing aircraft,” said Kieserman, who cautions, “Drones still have to comply with FAA regulations, so you still have to have someone who is qualified to be a drone pilot, and you still have to have airspace clearance in certain areas.”

Finally, using drones for damage assessments frees helicopter pilots and their aircraft to focus on life-saving SAR and other top-priority missions. During and after a disaster, any option that reduces the demand for manned aircraft and the resources they need is good news indeed.

American Red Cross and Drones

When it came to drone usage, 2017 was a big year for the American Red Cross. “We piloted two distinct drone operations during Hurricane Harvey,” Kieserman said. First, the American Red Cross deployed a tethered drone after the hurricane to do detailed residential damage assessment in communities that “we could not get into because they were still flooded, and we couldn’t drive by to do eyeball assessments,” he said. “While drones have the advantage, particularly tethered drones, of being able to go up to altitude, stay in one place, get 360-degree view, and be able to get a zoomed-in view at altitude, the real advantage of that is that you’re not rushing. You can really go home by home.”

Second, the American Red Cross used untethered drones after Hurricanes Harvey and Irma to obtain overall detailed damage assessments. “Because those drones are flying and moving through space, we really use that for more of an overview of where damage might be, as opposed to getting the detailed damage on individual homes that tethered drones are very helpful for,” Kieserman said.

Humanitarian Drones

The American Red Cross wasn’t the only group using drones for detailed damage assessments after Hurricane Harvey. Humanitarian Drones, a volunteer group of eight drone pilots and their drones came to Texas to lend a helping hand. “Our goal was to help the American Red Cross and other disaster officials accurately assess the affected areas with extremely high-resolution photographic maps, captured by our drones,” said Parker Gyokeres; a member of Humanitarian Drones, retired USAF photojournalist, and owner of Propellerheads Aerial Photography in Middleton, New York. The maps allowed rescue officials to know just how bad the damage was without having to drive into affected areas; saving them time and valuable resources.

Where Humanitarian Drones made the biggest difference was in storm-ravaged towns like Port Arthur, Texas. During the worst of Hurricane Harvey, Port Arthur Mayor Derrick Freeman posted on Facebook that “Our whole city is underwater right now...”

Afterwards, as the waters receded, Humanitarian Drones came to that city’s aid. “We created high-precision aerial maps, showing city officials which areas were flooded and which weren’t,” said group member/drone pilot Brian Scott, owner of commercial drone photography/videography company Upstate Aerial in Simpsonville, South Carolina. Despite the detail of the photos taken, the flyover to compile the maps only took about 90 minutes.

Next, the Humanitarian Drones group headed to the coastal city of Rockport, Texas. Using a variety of drones, primarily the DJI Phantom 4 Pro, the group’s eight drone pilots managed to visually assess and photograph 1,750 damaged properties in a matter of days. Each photo file was cross-referenced to GPS coordinates, to aid Rockport officials and home owners in recognizing property. Given how substantial the hurricane damage was, sometimes this was the only way to identify a specific property.

“Using our drones, we were able to shoot all sides of affected houses; showing their levels of damage in great detail,” said Gyokeres. With their blown-out windows and shattered structures, “Many of the buildings looked like something out of a war zone; especially to the three of us who had served with the military and seen such sites.”

Operating safely with other aircraft in the disaster zone’s busy airspace was just as important to Humanitarian Drones as shooting damage assessment imagery. This is why group members Jes Chosid and Brian Scott worked closely with the FAA in obtaining multiple drone flight authorizations daily.

The group also used a portable ADS-B (automatic dependent surveillance - broadcast) software program, titled “FlightHorizon GA,” to monitor local air traffic and monitor their drones’ positions relative to it in a safe, real-time manner. Developed by NASA and made by Vigilant Aerospace Systems, FlightHorizon GA provides both unmanned and manned operators with synthetic cockpit views and detect-and-avoid air collision capabilities on tablets or laptop computers.

“We equipped our drones with transponders that allowed us to track them in FlightHorizon GA, and alerted local air traffic control to our real-time positions,” said Ty Audronis, another member/pilot with Humanitarian Drones. “This was a very useful tool that enhanced our situational awareness, and the awareness of aircraft around us.”

By the time Humanitarian Drones wrapped up their volunteer damage assessments in Texas, they had aerially photographed thousands of sites -- and burned through 900 gallons of gas driving around the state. “Using drones is a very cost-effective way of putting eyes where you need them during and after disasters,” said Gyokeres. “It certainly allowed us to do a lot for the people in Texas.”

Drones as Team Players

The success achieved by Humanitarian Drones in compiling visual maps and damage assessments of hurricane-devastated areas—compiled by just eight volunteers and their personal drones—speaks to the tremendous power of this platform for aerial damage assessments. “A single drone with a small ground crew can cover most of the area or more of the area than a similar-sized larger team that is walking the ground and doing detailed damage assessment,” said the American Red Cross’s Kieserman. “The drone can do that when our teams can’t get to the streets due to flooding or a fire.” (He adds that, “One of the things we did in Texas after Hurricane Harvey was that we drove the drone, with a truck and a generator, from position to position so that we could really get overlapping, 360-degree views of the areas that were inaccessible.”)

At the same time, Kieserman notes that drones aren’t replacements for ground crews; instead, they are complementary resources. “There are times when you have to assign a person to walk down a street and there are other times when you can collect the data from a drone. You can either look at it in real time on a screen or you can collect that data and come back later and have the people who walked the street review and see everything they need to see, such as the external conditions of homes.”

This said, drones have their limitations. “One of the challenges that we have with drones is a similar challenge you have with other aviation assets: canopy and cloud cover,” said Kieserman. “Drones are a good way of dealing with higher-level cloud cover but when you start to get into dense fog or lower-level clouds, drones can be impaired just like a helicopter or a fixed-wing aircraft.” Large trees with their leaf canopies can also be an issue for drone image captures, especially old canopy, where you just can’t see through it, Kieserman adds.

All told, drones are proving themselves to be real team players during and after natural disasters; they add a layer of visual information for first responders and emergency management officials that didn’t exist before. “We founded Humanitarian Drones to show that drones could be a positive force in society,” said Parker Gyokeres. “Our work in Texas after Harvey proved this to be the case.”